Removed nocdn image for v6

packages/app/docker/README.md

@@ -11,7 +11,6 @@ Supported tags and respective Dockerfile links
 ------------------------------------------------
 
 * [`6.0.0`, `6.0`, `6`, `latest` (Dockerfile)](https://github.com/weseek/growi/blob/v6.0.0/packages/app/docker/Dockerfile)
-* [`6.0.0-nocdn`, `6.0-nocdn`, `6-nocdn`, `latest-nocdn` (Dockerfile)](https://github.com/weseek/growi/blob/v6.0.0/packages/app/docker/Dockerfile)
 * [`5.1.4`, `5.1`, `5`](https://github.com/weseek/growi/blob/v5.1.4/packages/app/docker/Dockerfile)
 * [`5.1.4-nocdn`, `5.1-nocdn`, `5-nocdn`](https://github.com/weseek/growi/blob/v5.1.4/packages/app/docker/Dockerfile)
 * [`4.5.23`, `4.5`, `4`, `latest` (Dockerfile)](https://github.com/weseek/growi/blob/v4.5.23/packages/app/docker/Dockerfile)